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Ravindranath, Sham. "How do Entangled Polymer Liquids Flow?" University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1281320132.
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Li, Xin. "Investigation of Non-linear Rheological Behavior of Polymeric Liquids." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1302374414.
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Livi, Sébastien. "Ionic liquids : multifunctional agents of the polymer matrices." Lyon, INSA, 2010. http://theses.insa-lyon.fr/publication/2010ISAL0101/these.pdf.
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An excellent thermal stability, a low saturated vapor pressure, a no flammability, a good ionic conductivity and the different cations / anions combinations possible of ionic liquids are currently the focus of the research. Because of its various benefits, they are as a new alternative in the polymer science, and particularly in the field of the nanocomposites where their use is currently limited to the function of surfactant for the layered silicates. However, before claiming the status of an alternative, it is necessary to highlight the benefits of their use on the final properties of polymer materials. Initially, the objective of this work was to synthesize different ionic liquids by the nature of cation and anion, but all bearing with long alkyl chains to allow greater compatibility with the matrix. Then, the excellent intrinsic properties of ionic liquids have motivated their use as structuring agents in a fluorinated aqueous dispersion. Thus, their role in ionic agents on the morphology, physical, thermal and mechanical properties was studied. In a second part, ionic liquids have been used as agents intercalating layered silicates and then confronted with conventional surfactants in order to prepare thermally stable clays for the preparation of nanocomposite thermoplastic / clay. In the last section, a small amount of organically modified clays were introduced by melt intercalation in two different matrices in order to highlight the effects of these new interfacial agents on the final properties of the materialUne excellente stabilité thermique, une faible pression de vapeur saturante, une ininflammabilité, une bonne conductivité ionique ainsi que les différentes combinaisons cations/anions possibles font des liquides ioniques l'objet d'un engouement grandissant de la Recherche. De part ces avantages, les LI se présentent comme une nouvelle voie dans le domaine des polymères, et en particulier dans le milieu des nanocomposites où leur utilisation est essentiellement limitée à la fonction de surfactant des silicates lamellaires. Néanmoins, avant de pouvoir prétendre à un statut d'alternative, il est nécessaire de mettre en évidence les effets bénéfiques de leur utilisation sur les propriétés finales des matériaux polymères. Dans un premier temps, l’objectif de ce travail a été de synthétiser des liquides ioniques différents par la nature de leur cation et anion mais tous porteurs de longues chaînes alkyles afin de permettre une meilleure compatibilité avec la matrice. Ensuite, les excellentes propriétés intrinsèques des liquides ioniques ont motivé leur utilisation comme agents structurants dans une dispersion aqueuse fluorée. Ainsi, leur rôle d’agents ioniques sur la morphologie, les propriétés physiques, thermiques et mécaniques a été étudié. Dans une seconde partie, les liquides ioniques ont été utilisés comme agents intercalants des silicates lamellaires puis confrontés aux surfactants conventionnels dans le but de préparer des argiles thermiquement stables pour la préparation de nanocomposites thermoplastiques/argiles. Dans une dernière partie, une faible quantité de ces argiles organiquement modifiées ont été introduites par intercalation à l'état fondu dans deux matrices différentes afin de mettre en évidence les effets de ces nouveaux agents interfaciaux sur les propriétés finales du matériau
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Sambriski, Edward John. "Theoretical models for the coarse-graining of polymeric liquids /." view abstract or download file of text, 2006. http://proquest.umi.com/pqdweb?did=1276397971&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.
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Thesis (Ph. D.)--University of Oregon, 2006.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 219-228). Also available for download via the World Wide Web; free to University of Oregon users.
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Yu, Zhou. "Molecular Structure and Dynamics of Novel Polymer Electrolytes Featuring Coulombic Liquids." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/87049.
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Polymer electrolytes are indispensable in numerous electrochemical systems. Existing polymer electrolytes rarely meet all technical demands by their applications (e.g., high ionic conductivity and good mechanical strength), and new types of polymer electrolytes continue to be developed. In this dissertation, the molecular structure and dynamics of three emerging types of polymer electrolytes featuring Coulombic liquids, i.e., polymerized ionic liquids (polyILs), nanoscale ionic materials (NIMs), and polymeric ion gels, were investigated using molecular dynamics (MD) simulations to help guide their rational design.
First, the molecular structure and dynamics of a prototypical polyILs, i.e., poly(1-butyl-3-vinylimidazolium hexafluorophosphate), supported on neutral and charged quartz substrates were investigated. It was found that the structure of the interfacial polyILs is affected by the surface charge on the substrate and deviates greatly from that in bulk. The mobile anions at the polyIL-substrate interfaces diffuse mainly by intra-chain hopping, similar to that in bulk polyILs. However, the diffusion rate of the interfacial mobile anions is much slower than that in bulk due to the slower decay of their association with neighboring polymerized cations.
Second, the structure and dynamics of polymeric canopies in the modeling NIMs where the canopy thickness is much smaller than their host nanoparticle were studied. Without added electrolyte ions, the polymeric canopies are strongly adsorbed on the solid substrate but maintain modest in-plane mobility. When electrolyte ion pairs are added, the added counter-ions exchange with the polymeric canopies adsorbed on the charged substrate. However, the number of the adsorbed electrolyte counter-ions exceeds the number of desorbed polymeric canopies, which leads to an overscreening of the substrate's charge. The desorbed polymers can rapidly exchange with the polymers grafted electrostatically on the substrate.
Finally, the molecular structure and dynamics of an ion gel consisting of PBDT polyanions and room-temperature ionic liquids (RTIL) were studied. First, a semi-coarse-grained model was developed to investigate the packing and dynamics of the ions in this ion gel. Ions in the interstitial space between polyanions exhibit distinct ordering, which suggests the formation of a long-range electrostatic network in the ion gel. The dynamics of ions slow down compared to that in bulk due to the association of the counter-ions with the polyanions' sulfonate groups. Next, the RTIL-mediated interactions between charged nanorods were studied. It was discovered that effective rod-rod interaction energy oscillates with rod-rod spacing due to the interference between the space charge near each rod as the two rods approach each other. To separate two rods initially positioned at the principal free energy minimum, a significant energy barrier (~several kBT per nanometer of the nanorod) must be overcome, which helps explain the large mechanical modulus of the PBDT ion gel reported experimentally.Ph. D.
Polymer electrolytes are an indispensable component in numerous electrochemical devices. However, despite decades of research and development, few existing polymer electrolytes can offer the electrochemical, transport, mechanical, and thermal properties demanded by practical devices and new polymer electrolytes are continuously being developed to address this issue. In this dissertation, the molecular structure and dynamics of three emerging novel polymer electrolytes, i.e., polymerized ionic liquids (polyILs), nanoscale ionic materials (NIMs), and polymeric ion gels, are investigated to understand how their transport and mechanical properties are affected by their molecular design. The study of polyILs focused on the interfacial behavior of a prototypical polyILs supported on neutral and charged quartz substrates. It was shown that the structure and diffusion mechanism of the interfacial polyILs are sensitive to the surface charges of the substrate and can deviate strongly from that in bulk polyILs. The study of NIMs focused on how the transport properties of the dynamically grafted polymers are affected by electrolyte ion pairs. It was discovered that the contaminated ions can affect the conformation the polymeric canopies and the exchange between the “free” and “grafted” polymers. The study of polymeric ion gels focused on the molecular and mesoscopic structure of the ionic liquids in the gel and the mechanisms of ion transport in these gels. It was discovered that the ions exhibit distinct structure at the intermolecular and the interrod scales, suggesting the formation of extensive electrostatic networks in the gel. The dynamics of ions captured in simulations is qualitatively consistent with experimental observations.
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Tretyakov, Nikita. "Molecular Dynamics simulations of polymer liquids on substrates of different topography." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-F67D-3.
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Hunt, Thomas A. "Theory and simulation of polymer liquids under extensional and shear flows." Swinburne Research Bank Swinburne Research Bank, 2008. http://hdl.handle.net.
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Thesis (PhD) - Swinburne University of Technology, Centre for Molecular Simulation - 2008.Submitted in fulfilment of requirements for the degree Doctor of Philosophy, Centre for Molecular Simulation, Faculty of Information and Communication Technologies, Swinburne University of Technology, 2008. Typescript. Bibliography: p. 206-226.
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Mohan, Aruna 1981. "Field-driven dynamics of dilute gases, viscous liquids and polymer chains." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42429.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2007.Includes bibliographical references (p. [131]-136).
This thesis is concerned with the exploration of field-induced dynamical phenomena arising in dilute gases, viscous liquids and polymer chains. The problems considered herein pertain to the slip-induced motion of a rigid, spherical or nonspherical particle in a fluid in the presence of an inhomogeneous temperature or concentration field or an electric field, and the dynamics of charged polymers animated by the application of an electric field. The problems studied in this thesis are unified by the existence of a separation of length scales between the macroscopic phenomena of interest and their microscopic underpinnings, and are treated by means of coarse-graining principles that exploit this scale separation. Specifically, the first part of this thesis investigates the dynamics caused by the existence of a slip velocity at a fluid-solid interface. The macroscopic slip boundary condition obtains from the asymptotic matching of the velocity within the microscale layer of fluid adjoining the solid surface, and the velocity in the bulk fluid. In the case of a gas, the microscopic length scale is constituted by the mean free path, and the layer of gas adjoining the solid boundary having a thickness of the order of the mean free path is referred to as the Knudsen layer. The parameter representing the ratio of the mean free path to the macroscopic length scale is the Knudsen number, denoted Kn. The widely-used Navier-Stokes and Fourier equations are valid away from the solid boundary at distances large compared to the mean free path in the limit Kn < 1, and necessitate the imposition of continuum boundary conditions on the gas velocity and temperature at the outer limit of the Knudsen layer. These macroscopic equations are typically solved subject to the no-slip of velocity and the equality of the gas and solid temperatures at the solid boundary.
(cont) However, as first pointed out by Maxwell, the no-slip boundary condition fails to explain experimentally observed phenomena when imposed at the surface of a nonuniformly heated solid, and must be replaced by the thermal slip condition obtained via the asymptotic matching of the velocity within the Knudsen layer with that in the bulk gas. Slip has also been proposed to occur at liquid-solid boundaries under conditions of inhomogeneous temperature or concentration. In this thesis, we extend Faxen's laws for the force and torque acting on a spherical particle in a fluid with a prescribed undisturbed flow field to account for the existence of fluid slip at the particle surface. Additionally, we investigate the effect of particle asymmetry by studying the motion of a slightly deformed sphere in a fluid having a uniform unperturbed flow field, and demonstrate that the velocity of a force- and torque-free particle is independent of its size or shape. While the slip-induced motions studied in this thesis are presented in the context of thermally-induced slip arising from the existence of a temperature gradient, the results are equally applicable to more general phoretic transport, encompassing the electrokinetic slip condition employed in the treatment of charged particle dynamics in an electrolytic liquid. Analogous to the thermal slip condition imposed on a gas at the outer limit of the Knudsen layer, the electrokinetic slip condition is imposed at the outer limit of the layer of counterions surrounding a charged surface in an electrolytic liquid. The studies presented in this thesis have potential applications in aerosol and colloid technology, in the nonisothermal transport of particulates in porous media and MEMS devices, and in the electrophoresis of charged bodies. The behavior of a charged polymer molecule in an electric field constitutes the subject of the second part of this thesis.
(cont) Motivated by the medical and technological necessity to effect the size-separation of DNA chains in applications ranging from the Human Genome Project to DNA-based criminology, we consider specifically the dynamics of electric-field driven DNA chains in size-based separation devices. The conventional technique of constant-field gel electrophoresis is ineffective in achieving the separation of long DNA chains whose sizes exceed a few tens of kilobase pairs, owing to the fact that the velocity becomes independent of chain size for long chains in a gel. This limitation of gel electrophoresis has spurred the development of alternative separation devices, such as obstacle courses confined to microchannels wherein the obstacles may be either microfabricated or formed from the self-assembly of paramagnetic beads into columns upon the imposition of a magnetic field transverse to the channel plane. Size separation in the latter devices arises from the fact that longer chains, when driven through the channel by an applied electric field, are more likely to collide with the obstacles and take longer to disentangle from the obstacle once a collision has occurred, relative to shorter chains. Consequently, a longer chain requires more time to traverse the array compared to a shorter chain. As a model for the transient chain stretching occurring subsequent to the collision of an electrophoresing DNA molecule with an obstacle, we study the unraveling of a single, tethered polymer molecule in a uniform solvent flow field. In the context of a polymer, the microscopic length scale is associated with the size of a monomer. We, however, employ a coarse-grained representation wherein the polymer is modeled by a chain of entropic springs connected by beads, with each bead representing several monomers, thereby enabling a continuum description of the solvent. We adopt the method of Brownian dynamics applied to the bead-spring model of the polymer chain.
(cont) We consider both linear force-extension behavior, representative of chain stretching in a weak field, and the finitely-extensible wormlike chain model of DNA elasticity, which dominates chain stretching under strong fields. The results yield insight into the mechanism of tension propagation during chain unraveling, and are more generally applicable to situations involving transient stretching, such as chain interactions arising in entangled polymer solutions. We next conduct investigations of chain dynamics in obstacle-array based separation devices by means of coarse-grained stochastic modeling and Brownian dynamics simulation of a chain in a self-assembled array of magnetic beads, and predict the separation achievable among different chain sizes. We examine the influence of key parameters, namely, the applied electric field strength and the spacing between obstacles, on the separation resolution effected by the device. Our results elucidate the mechanisms of DNA dynamics in microfluidic separation devices, and are expected to aid in the design of DNA separation devices and the selection of parameters for their optimal operation.
by Aruna Mohan.
Ph.D.
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Warner, Julia D. "Transport analysis in polymeric liquids and films: Investigations in ionic mobility isolation techniques and permeability control." W&M ScholarWorks, 2003. https://scholarworks.wm.edu/etd/1539623430.
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An in situ measurement technique that isolates the mobility of charge carriers is described and analyzed. The technique allows significant improvement over conductivity measurements to monitor changes in the physical properties and state of a material as it cures. This is essential in systems where Ni, the number of charge carriers, cannot be assumed constant such as during cure of epoxies, urethanes and polyimides.;Currently, there is an assumption made in the literature that the number of charge carriers present in a curing material is constant when conductivity is used as an in situ measurement technique to monitor changes in mobility. Ion mobility, time of flight (ITOF) measurements, which are described here, are an appropriate technique to isolate and measure particle mobility due to changes in the state of the material. The ITOF technique, coupled with the measurement of sigma, the ionic conductivity, allows one to measure separately changes in the mobility and the number of charge carriers due to curing or changes in temperature. This is possible since conductivity is the product of the number of charge carriers and their mobility. Length of pulse, strength of applied field, sensor geometry, and temperature/viscosity are examined to determine optimum parameters of measurement for both a simple non-curing system, and more complex, hydrogen-bonded epoxy.;The second focus of this thesis is our recently developed single stage in situ synthesis of hybrid membranes comprised of nanometer-sized metal and metal oxide particles in polyimides. The major goal is development of polymer based structural materials designed to achieve exceptional performance properties regarding gas permeability and gas separation selectivity, particularly in regard to their thickness, modulus, and strength to weight ratio. We investigate hybrid inorganic-polyimide films where the nanoparticle inorganic phases are of two types: (1) nanometer-sized rare earth (lanthanum, gadolinium and holmium) oxide molecular clusters and (2) nanometer-sized palladium and silver metal clusters. For the polymeric phase we used aromatic poly(amic acid)s-polyimides because of their strength and chemical and thermal stability.
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Lee, Minjae. "Design, Synthesis and Self-Assembly of Polymeric Building Blocks and Novel Ionic Liquids, Ionic Liquid-Based Polymers and Their Properties." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/77166.
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The convergence of supramolecular and polymer sciences has led to the construction of analogs of traditional covalently-constructed polymeric structures and architectures by supramolecular methods. Host-guest complexations of polymers are also possible through well-defined synthesis of polymeric building blocks, for novel supramolecular polymers.
Monotopic polymeric building blocks were synthesized by controlled radical polymerizations with a crown or paraquat initiator. The combinations of terminal and central functionalities of host and guest polymeric building blocks provided chain-extended and tri-armed homopolymers, and diblock and tri-armed copolymers.
A supramolecular graft copolymer was formed from a main-chain poly(ester crown ether) and a paraquat terminated polystyrene. This comb-like copolymer was characterized by a large viscosity increase. A four-armed polystyrene-b-poly(n-butyl methacrylate) was synthesized from a pseudorotaxane macroinitiator derived from a complex of a crown-centered polystyrene and a dufunctional paraquat compound. A single peak with higher molecular weight from size exclusion chromatography proved the copolymer formation.
Supramolecular interactions enhance the ionic conductivity of semi-crystalline ionic polymers; the ionic conductivity of a C₆-polyviologen and dibenzo-30-crown-10 mixture was 100 times higher than the polyviologen itself. However, ionic conductivities of amorphous polyviologens with polyethers were influenced only by glass transition temperature changes.
New imidazolium ionic liquid monomers and imidazolium based polymers were synthesized for potential applications in electroactive devices, such as actuators. Structure-property relationships for pendant imidazolium polyacrylates and main-chain imidazolium polyesters were investigated. Terminal ethyleneoxy moeties enhanced ionic conduction 2~3 times; however, the alkyl chain length effect was negligible. For the imidazoium polyesters, higher ion conductivities result from 1) mono-imidazolium over bis-imidazolium, and 2) bis(trifluoromethanesulfonyl)imide polymers over hexafluorophosphate analogs. A semi-crystalline hexafluorophosphate polyester with C₁₀-sebacate-C₁₀, displayed 400-fold higher ionic conductivity than the amorphous C₆-sebacate-C₆ analogue, suggesting the formation of a biphasic morphology in the former polyester.
New dicationic imidazolium salts have interesting features. 1,2-Bis[N-(N'-alkylimidazoilum)]ethane salts stack well in the solid state and possess multiple solid-solid phase transitions. They complex with dibenzo-24-crown-8 and a dibenzo-24-crown-8 based pyridyl cryptand with Ka = ~30 and 360 M¹, respectively. Some of these dicationic imidazolium salts have low entropies of fusion, typical of plastic crystals.
These newly discovered imidazolium homopolymers have ionic conductivities up to 10⁴ (S cm⁻¹); however, better properties are still required. Well-designed block copolymers should provide both good electrical and mechanical properties from bicontinuous morphologies, such ion channels.Ph. D.
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KIATKITTIKUL, PISIT. "A study on nonhumidified fuel cells using fluorohydrogenate ionic liquids." Kyoto University, 2015. http://hdl.handle.net/2433/199414.
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Stefin-Tyree, Amanda Joy. "Investigating Interfacial Behaviors of Silicon Dioxide in Contact with Liquids and Polymers in Contact with Water." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1627404674037109.
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McCarty, James. "Multiscale Modeling and Thermodynamic Consistency between Soft-Particle Representations of Macromolecular Liquids." Thesis, University of Oregon, 2014. http://hdl.handle.net/1794/17906.
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Coarse-graining and multi-scale approaches are rapidly becoming important tools for computer simulations of large complex molecular systems. Such theoretical models are powerful tools because they allow one to probe the essential features of a complex, many-bodied system on length and time scales over which emergent phenomena may occur. Because of the computational advantages and fundamental insight made available through coarse-grained methods, a vast array of various phenomenological potentials to describe coarse-grained interactions have been developed; nonetheless, the ability of these potentials to provide quantitative information about several different properties of the same system is not evident. On a theoretical level, it is not well-understood how small correlations in the long-range structure propagate through the coarse-graining procedure into the effective potential and lead to incorrect thermodynamics. Taking an alternative approach, this dissertation will discuss an analytical coarse-graining method for synthetic polymer chains of specific chemical structure, where a group of atoms on a polymer chain are represented by a variable number of soft interacting effective sites. The approach is based in liquid-state theory, providing a theoretical framework to address questions of thermodynamic consistency. It will be shown that the proposed method of coarse-graining maintains thermodynamic consistency for a variety of polymer models. In a multi-scale modeling scheme simulations of the same system represented by several different levels of detail may be joined to provide a complete description of the system at all length and time scales of interest.
This dissertation includes previously published and unpublished co-authored material.
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Mlynarczyk, Paul John. "The nature and determination of the dynamic glass transition temperature in polymeric liquids." Kansas State University, 2014. http://hdl.handle.net/2097/17782.
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Master of ScienceDepartment of Chemical Engineering
Jennifer L. Anthony
A polymer has drastically different physical properties above versus below some characteristic temperature. For this reason, the precise identification of this glass transition temperature, T[subscript]g, is critical in evaluating product feasibility for a given application. The objective of this report is to review the behavior of polymers near their T[subscript]g and assess the capability of predicting T[subscript]g using theoretical and empirical models. It was determined that all polymers begin to undergo structural relaxation at various temperatures both nearly above and below T[subscript]g, and that practical assessment of a single consistent T[subscript]g is successfully performed through consideration of only immediate thermal history and thermodynamic properties. It was found that the best quantitative structure-property relationship (QSPR) models accurately predict T[subscript]g of polymers of theoretically infinite chain length with an average error of less than 20 K or about 6%, while T[subscript]g prediction for shorter polymers must be done by supplementing these T[subscript]g (∞) values with configurational entropy or molecular weight relational models. These latter models were found to be reliable only for polymers of molecular weight greater than about 2,000 g/mol and possessing a T[subscript]g (∞) of less than about 400 K.
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Ahmed, Ejaz, Joachim Breternitz, Matthias Friedrich Groh, and Michael Ruck. "Ionic liquids as crystallisation media for inorganic materials." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138932.
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Ionic liquids (ILs) have made a great impact on materials science and are being explored for potential applications in several disciplines. In this article, we briefly highlight the current state-of-the-art techniques employing ILs as new crystallisation media, working as neutral solvent, template or charge compensating species. The use of an IL as environmental friendly solvent offers many advantages over traditional crystallisation methods. The change from molecular to ionic reaction media leads to new types of materials being accessible. Room temperature ILs have been found to be excellent solvent systems for the crystallisation of a wide range of substances and morphologies ranging from nanoscopic crystals to micro- and even to macroscopic crystals. Moreover, high temperature routes, such as crystallisation from melts or gas phase deposition, have been replaced by convenient room or low temperature syntheses, employing ILs as reaction mediaDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Ahmed, Ejaz, Joachim Breternitz, Matthias Friedrich Groh, and Michael Ruck. "Ionic liquids as crystallisation media for inorganic materials." Royal Society of Chemistry, 2012. https://tud.qucosa.de/id/qucosa%3A27794.
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Ionic liquids (ILs) have made a great impact on materials science and are being explored for potential applications in several disciplines. In this article, we briefly highlight the current state-of-the-art techniques employing ILs as new crystallisation media, working as neutral solvent, template or charge compensating species. The use of an IL as environmental friendly solvent offers many advantages over traditional crystallisation methods. The change from molecular to ionic reaction media leads to new types of materials being accessible. Room temperature ILs have been found to be excellent solvent systems for the crystallisation of a wide range of substances and morphologies ranging from nanoscopic crystals to micro- and even to macroscopic crystals. Moreover, high temperature routes, such as crystallisation from melts or gas phase deposition, have been replaced by convenient room or low temperature syntheses, employing ILs as reaction media.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Clark, Anthony. "Properties of Effective Pair Potentials that Map Polymer Melts onto Liquids of Soft Colloid Chains." Thesis, University of Oregon, 2013. http://hdl.handle.net/1794/13005.
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The ability to accurately represent polymer melts at various levels of coarse graining is of great interest because of the wide range of time and length scales over which relevant process take place. Schemes for developing effective interaction potentials for coarse-grained representations that incorporate microscopic level system information are generally numerical and thus suffer from issues of transferability because they are state dependent and must be recalculated for different system and thermodynamic parameters. Numerically derived potentials are also known to suffer from representability problems, in that they may preserve structural correlations in the coarse-grained representation but many often fail to preserve thermodynamic averages of the coarse-grained representation. In this dissertation, analytical forms of the structural correlations and effective pair potentials for a family of highly coarse-grained representations of polymer melts are derived. It is shown that these effective potentials, when used in mesoscale simulations of the coarse-grained representation, generate consistent equilibrium structure and thermodynamic averages with low level representations and therefore with physical systems. Furthermore, analysis of the effective pair potential forms shows that a small long range tail feature that scales beyond the physical range of the polymer as the fourth root of the number of monomers making up the coarse-grained unit dominates thermodynamic averages at high levels of coarse graining. Because structural correlations are extremely insensitive to this feature, it can be shown that effective interaction potentials derived from optimization of structural correlations would require unrealistically high precision measurements of structural correlations to obtain thermodynamically consistent potentials, explaining the problems of numerical coarse-graining schemes.
This dissertation includes previously published and unpublished co-authored material.
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Saheb, Amir Hossein. "Sensing materials based on ionic liquids." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24789.
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Thesis (Ph.D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009.Committee Chair: Janata, Jiri; Committee Member: Bunz, Uwe; Committee Member: Collard, David; Committee Member: Josowicz, Mira; Committee Member: Kohl, Paul.
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Deng, Rui. "Potential for functionalised ionic liquids in olefin/paraffin separation using composite polymer membranes, extraction or reactive distillation." Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601147.
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In this work, non-membrane and membrane methods were utilized to investigate the separations of olefin/paraffin and several industrial gas pairs. The non-membrane methods section investigated different methods used for olefin and paraffin separations which include liquid extraction and reactive distillation. I -hexene and n-hexane were selected as the olefin and paraffin representatives and were tested in all the liqu id extraction and distillation separation experiments. In the liquid extraction separation systems, three different extractants were used namely [Bmim][N Tf2L silver nitrate salt of MIM-PS (1-( 1-methyl-3-im idazolio)propane-3 -su lfonate) dissolved in [Bmim][HS041 mixtures and [BmimHBF,l cont aining AgBF4• Distribution coefficients of I -hexene and n-hexane were ca lculated for each and selectivities were also obtained from the distribution coefficient data. For the distillation separation method, silica supported ionic liquids (SILs) of [Bmim][NTf21 and [Bmim][BF41 containing AgBF4 were prepared and adopted as the reactive packing to aid in the separation of the olefin. Vapour-liquid equilibrium (VlE) data were studied for the ordinary distillation without Sils packing as well as for the different reactive distillation systems. TPU (Thermal polyurethane) and PSF (polysulfone) were selected as the polymer materials to carry out the olefin/paraffin permeabilities and separation effects tests in the membrane sepa ration section. Casting and coating composite polymer/ionic liquid membranes of different weight ratios of polymer to ionic liquid were made to undertake the olefin/paraffin separation tests. Ethane/ethylene and propane/propylene gas pairs were selected as the olefin/ paraffin rep resentatives. Co mposite TPU/AgOTf/[Bmim+OTfj and TPU/AgPFt;/ [Bmim+PF6-1 membranes were also pre pa red and tested for olef in/paraffin separations. Diffe rent weight ratios of polymer to silver salt and mol ratios of silver salt to ionic liquid were chosen to synthesize the composite polymer/silver salt/ionic li quid membranes. Finally, the olefin/ paraffin separation mechanisms were discussed.
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Kalaikadal, Deepak Saagar. "Investigation of Bubble Dynamics in Pure Liquids and Aqueous Surfactant / Polymer Solutions Under Adiabatic and Diabatic Conditions." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1525167893347615.
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Basnayaka, Punya A. "Development of Nanostructured Graphene/Conducting Polymer Composite Materials for Supercapacitor Applications." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4864.
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The developments in mobile/portable electronics and alternative energy vehicles prompted engineers and researchers to develop electrochemical energy storage devices called supercapacitors, as the third generation type capacitors. Most of the research and development on supercapacitors focus on electrode materials, electrolytes and hybridization. Some attempts have been directed towards increasing the energy density by employing electroactive materials, such as metal oxides and conducting polymers (CPs). However, the high cost and toxicity of applicable metal oxides and poor long term stability of CPs paved the way to alternative electrode materials. The electroactive materials with carbon particles in composites have been used substantially to improve the stability of supercapacitors. Furthermore, the use of carbon particles and CPs could significantly reduce the cost of supercapacitor electrodes compared to metal oxides. Recent developments in carbon allotropes, such as carbon nanotubes (CNTs) and especially graphene (G), have found applications in supercapacitors because of their enhanced double layer capacitance due to the large surface area, electrochemical stability, and excellent mechanical and thermal properties.
The main objective of the research presented in this dissertation is to increase the energy density of supercapacitors by the development of nanocomposite materials composed of graphene and different CPs, such as: (a) polyaniline derivatives (polyaniline (PANI), methoxy (-OCH3) aniline (POA) and methyl (-CH3) aniline (POT), (b) poly(3-4 ethylenedioxythiophene) (PEDOT) and (c) polypyrrole (PPy). The research was carried out in two phases, namely, (i) the development and performance evaluation of G-CP (graphene in conducting polymers) electrodes for supercapacitors, and (ii) the fabrication and testing of the coin cell supercapacitors with G-CP electrodes.
In the first phase, the synthesis of different morphological structures of CPs as well as their composites with graphene was carried out, and the synthesized nanostructures were characterized by different physical, chemical and thermal characterization techniques, such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), UV-visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, BET surface area pore size distribution analysis and Thermogravimetric Analysis (TGA). The electrochemical properties of G-CP nanocomposite-based supercapacitors were investigated using Cyclic Voltammetry (CV), galvanostatic charge-discharge and Electrochemical Impedance Spectroscopy (EIS) techniques in different electrolytes, such as acidic (2M H2SO4 and HCl), organic ( 0.2 M LiClO4) and ionic liquid (1M BMIM-PF6) electrolytes.
A comparative study was carried out to investigate the capacitive properties of G-PANI derivatives for supercapacitor applications. The methyl substituted polyaniline with graphene as a nanocomposite (G-POT) exhibited a better capacitance (425 F/g) than the G-PANI or the G-POA nanocomposite due to the electron donating group of G-POT. The relaxation time constants of 0.6, 2.5, and 5s for the G-POT, G-PANI and G-POA nanocomposite-based supercapacitors were calculated from the complex model by using the experimental EIS data.
The specific capacitances of two-electrode system supercapacitor cells were estimated as 425, 400, 380, 305 and 267 F/g for G-POT, G-PANI, G-POA, G-PEDOT and G-PPy, respectively. The improvements in specific capacitance were observed due to the increased surface area with mesoporous nanocomposite structures (5~10 nm pore size distribution) and the pseudocapacitance effect due to the redox properties of the CPs. Further, the operating voltage of G-CP supercapacitors was increased to 3.5 V by employing an ionic liquid electrolyte, compared to 1.5 V operating voltage when aqueous electrolytes were used. On top of the gain in the operating voltage, the graphene nano-filler of the nanocomposite prevented the degradation of the CPs in the long term charging and discharging processes.
In the second phase, after studying the material's chemistry and capacitive properties in three-electrode and two-electrode configuration-based basic electrochemical test cells, coin cell type supercapacitors were fabricated using G-CP nanocomposite electrodes to validate the tested G-CPs as devices. The fabrication process was optimized for the applied force and the number of spacers in crimping the two electrodes together. The pseudocapacitance and double layer capacitance values were extracted by fitting experimental EIS data to a proposed equivalent circuit, and the pseudocapacitive effect was found to be higher with G-PANI derivative nanocomposites than with the other studied G-CP nanocomposites due to the multiple redox states of G-PANI derivatives. The increased specific capacitance, voltage and small relaxation time constants of the G-CPs paved the way for the fabrication of safe, stable and high energy density supercapacitors.
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Tretyakov, Nikita [Verfasser], Marcus [Akademischer Betreuer] Müller, and Reiner [Akademischer Betreuer] Kree. "Molecular Dynamics simulations of polymer liquids on substrates of different topography / Nikita Tretyakov. Gutachter: Marcus Müller ; Reiner Kree. Betreuer: Marcus Müller." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://d-nb.info/1044051809/34.
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Yang, Jing. "Phosphonium ionic liquids : Versatile nanostructuration and interfacial agents for poly(vinylidene fluoride-chlorotrifluoroethylene)." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI072/document.
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Ce travail de thèse porte sur la compréhension du rôle polyvalent des liquides ioniques (LIs) phosphonium comme agents de nanostructuration et interfaciaux pour la matrice polymère fluorée poly(fluorure de vinylidène-chlorotrifluoroéthylène) (P(VDF-CTFE)). Dans un premier temps, deux LIs phosphonium avec des fonctionnalités différentes générant un encombrement stérique et des fonctions dipolaire additionnelles sont tout d'abord incorporés dans la matrice P(VDF-CTFE) pour préparer des films de polymère additives. La structure de la phase cristalline, la morphologie issue de la dispersion et le comportement de cristallisation sont finement caractérisés dans le but de fournir une compréhension fuie et complète du rôle joué par le LI sur la nanostructuration. Dans un second temps, le rôle d’agent interfacial du LI est étudié avec un LI phosphonium fluoré comprenant un cation combinant trois phényles et une chaîne fluorée courte.Ce LI est utilise pour modifier la surface de l'oxyde de graphène (GO) et de l'oxyde de graphène réduit (rGO) afin de rendre ces nanocharges fonctionnelles et les incorporer dans la matrice P(VDF-CTFE). Ainsi, des films composites de P(VDF-CTFE)/graphène avec différentes teneurs en nanocharges sont préparés et une caractérisation fuie de la structure et des propriétés est entreprise afin de mieux comprendre les mécanisme d’interaction interfaciale et leurs influences sur les films composites, tels que la structure de la phase cristalline, le comportement de cristallisation, la relaxation des chaînes, la morphologie et les propriétés diélectriques finalesThis thesis work deals with an understanding of the versatile roles of phosphonium ionic liquids (ILs) as nanostructuration and interfacial agents for the fluorinated polymer matrix, i.e.,poly(vinylidene fluoride-chlorotrifluoroethylene) (P(VDF-CTFE)). In this context, two phosphonium ILs with different functionalities in steric hindrance and extra dipolar groups are firstly incorporated in P(VDF-CTFE) matrix to prepare polymer films. The crystalline phase structure, dispersion morphology and crystallization behavior are finely characterized with the goal of providing a full and deep understanding of the versatile and tunable nanostructuration effect of phosphonium ILs. Subsequently, in order to elucidate the mechanism of interfacial influence of IL, a fluorinated phosphonium IL with a cation structure combining three phenyls and a short fluorinated chain is added on the surface of graphene oxide (GO) and reduced graphene oxide (rGO), making them as functional nanofillers to be incorporated into P(VDF-CTFE) matrix. Thus,P(VDF-CTFE)/graphene composite films with different filler contents are prepared in order to investigate the mechanism of interfacial interaction and its influence on the composite films, such as crystalline phase structure, crystallization behavior, chain segmental relaxation behavior, dispersion morphology and the final dielectric properties
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Vnuková, Zuzana. "Vliv mazacích kapalin na průvodní veličiny tváření závitů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-444293.
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The main task of this work was to compare the being used process fluids in mechanical engineering with a focus on polymer and additive fluids. Selected polymer and nanoadditive fluids were compared based on a thread forming test, during which different concentrations of individual fluids were tested. All data from experiments were evaluated, assessed in terms of their properties, and recommended for further practice.
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Fedosse, Zornio Clarice. "Ionic liquids as multifuncional additives for poly(methyl methacrylate)-based materials." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI041/document.
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La vaste gamme de combinaisons possibles de cations et anions, ainsi que les excellentes propriétés intrinsèques des liquides ioniques (LIs) peuvent être considérées comme les principaux facteurs qui ont conduit au développement d’une recherche utilisant des LIs comme additifs des matériaux polymère. Ainsi, l'objectif principal de ce travail est d'explorer le rôle de la nature du cation et/ou du anion du LI sur les propriétés des matériaux basées de poly (méthacrylate de méthyle) (PMMA). Dans une première partie, des LIs de type imidazolium et ammonium ont été incorporés au PMMA et des caractérisations morphologiques et structurales ont été effectuées afin de comprendre leur impact sur les propriétés thermiques, viscoélastiques et mécaniques des matériaux résultants. Dans la section suivante, la capacité de ces LIs à base d'imidazolium et d'ammonium en tant qu’agents interfaciaux à la surface de la silice a été évaluée. Sub-micro et nanoparticules de silice, ainsi que les LIs, ont été incorporées dans une matrice de PMMA afin de préparer des composites. L'amélioration des propriétés des matériaux ont été discutées en fonction du degré auquel chaque LI influence la compatibilité entre les particules et la matrice polymère. De plus, ces composites ont été exposés au dioxyde de carbone en état supercritique (scCO2) pour utiliser celui-ci comme agent moussant et ainsi produire des matériaux expansés. Le rôle du LI et des particules de silice pour structurer les matériaux expansés a été analysé. Dans la dernière partie de cette étude, le scCO2 est utilisé comme milieu de réaction pour la modification chimique par greffage de la surface des nanoparticules de silice par des LIs de type imidazolium, contenant également des groupes hydrolysables et différentes chaînes alkyles. Le rôle de la pression et la quantité de LI ajoutées au milieu de réaction, ainsi que la longueur de la chaîne alkyle des LIs se sont avérées essentielles pour contrôler le degré de fonctionnalisation des nanoparticules. Enfin, ces nanoparticules modifiées ont été incorporées dans une matrice PMMA. Des analyses de morphologie ont été utilisées pour évaluer la dispersion des particules dans la matrice et les propriétés physico-chimiques de ces matériaux ont été également étudiéesThe large array of cation/anion combinations, and the excellent intrinsic properties of ionic liquids (ILs) open a large range of possibilities in their use as additives to polymer materials. Thus, the main objective of this work is to explore the role of both the cation and anion of a series of ILs on the properties of poly(methyl methacrylate) (PMMA)-based materials. In a first approach, low amounts of imidazolium and ammonium-based ILs were incorporated as additives to PMMA in the molten state. Morphological and structural characterizations were developed in order to understand the impact of the presence of such ILs on the thermal and mechanical properties of the resulting materials. Then, in the following section, the ability of the same imidazolium and ammonium-based ILs as physical modifiers of silica surface was evaluated. In such an approach, ILs were supposed to act as interfacial agents. Sub-micron and nanosize silica particles were used to prepare PMMA composites. Thus, the extents of each IL improve the interfacial interaction between PMMA and silica particles were discussed. In addition, supercritical carbon dioxide (scCO2) was used as foaming agent to produce foamed PMMA-based composites. In such a case, the combined effect of the presence of ILs and silica particles was analyzed regarding the morphology of the foamed structures. In the last section, scCO2 was used as reaction medium, in an environmental friendly approach, to chemically modify silica nanoparticles using a series of imidazolium IL-functionalized silanes (with different alkyl chain lengths). Thermogravimetric analysis (TGA) was used to highlight the effect of the working pressure and the content of such ILs in the reaction medium. The effect of the alkyl chain length on the grafting density of the resulting nanoparticles was also discussed. Finally, novel PMMA-based nanocomposites were prepared by the incorporation of such grafted nanoparticles. Transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) analyses were used to evaluate the state of dispersion of the particles into the polymer matrix. Moreover, the thermal, rheological and mechanical properties of the materials were studied
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Costa, Luciano Tavares da. "Simulação computacional de eletrólitos poliméricos baseados em poli (oxietileno) e líquidos iônicos." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/46/46132/tde-19102007-074147/.
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Simulações por Dinâmica Molecular (MD) de eletrólitos poliméricos baseados em poli (oxietileno), POE, e líquidos iônicos derivados do cátion 1-alquil-3-metilimidazólio e ânion hexafluorfosfato foram realizadas. Os parâmetros do potencial intermolecular e intramolecular foram obtidos de simulações MD prévias, a partir de um modelo de átomos unidos para POE e cátions imidazólio, ou seja, átomos de hidrogênio não são considerados explicitamente. Investigação sistemática da concentração de líquido iônico (LI), temperatura, e comprimento da cadeia 1-alquil, [1,3-dimetilimidazólio]PF6 e [1-butil-3-metilimidazólio]PF6, bem como seus efeitos sobre a estrutura de equilíbrio foram realizadas, constatando completa dispersão dos líquidos iônicos na matriz polimérica. Foram observadas mudanças conformacionais na cadeia de POE, devido à interação POE-LI. Além disso, os sistemas apresentaram ordem em escala intermediária (IRO) similar aos eletrólitos poliméricos de sais inorgânicos simples. Estes resultados foram motivadores para realização de ensaios experimentais com de poli (etileno glicol) dimetil éter, PEGdME, e hexafluorfosfato de 1-butil-3-metilimidazólio, caracterizado por análises térmicas TG e DSC, difração de raio-X e espectroscopia por impedância eletroquímica. Correlações com a previsão teórica foram reveladas, em especial quanto à coordenação POE-LI, que ocorre principalmente na fase amorfa. Condutividades da ordem de 10-3 S.cm-1 a altas temperaturas foram observadas. O estudo computacional sobre a dinâmica dos sistemas revelou mobilidade iônica em POE/[bmim]PF6 maior que em POE/[dmim]PF6, além de mostrar que a adição de líquido iônico ao polímero causa diminuição na dinâmica das cadeias de POE. Condutividades calculadas para POE/[bmim]PF6 estão em concordância qualitativa com as obtidas para o sistema PEGdME-[bmim]PF6. A redução dos pares iônicos frente aos eletrólitos poliméricos de sais inorgânicos é a distinta evolução no tempo da função de van Hove para ânions e cátions, bem como a razão κ/κNE maior, por exemplo, em comparação ao sistema POE- LiClO4.Molecular dynamics simulations of polymer electrolytes based on poly (oxyethylene), POE, and ionic liquids derived from 1-alkyl-3-methylimidazolium hexafluorophosphate were performed. We used united atom models, i.e. hydrogen atoms of the PEO chain and 1,3-dialkylimidazolium cations are not explicitly considered. All of the potential parameters for intramolecular terms can be found in previous MD simulations of POE-LiCLO4 and ionic liquids systems. A systematic investigation of ionic liquid concentration, temperature, and the 1-alkyl-chain length, [1,3-dimethylimidazolium]PF6, and [1-butyl-3-methylimidazolium]PF6, effects on resulting equilibrium structure is provided. It is shown that the ionic liquid is dispersed in the polymeric matrix and conformational changes on PEO chains upon addition of the ionic liquid are identified. Long-range correlations are assigned to non-uniform distribution of ionic species within the simulation box. Experimental data were obtained from thermal analysis, x-ray diffraction and electrochemical impedance spectroscopy from poly (ethylene glycol) dimethyl ether, PEGdME, and 1-butyl-3-methylimidazolium hexafluorophosphate. Correlations with previous theoretical results were revealed and coordination of the IL by the polymer occurs mainly in the amorphous phase. It has been obtained ionic conductivity κ ~ 10-3 S.cm-1 for polymer electrolytes at high temperatures. Ionic mobility in PEO/[bmim]PF6 is higher than in PEO/[dmim]PF6 and the structural relaxation in PEO/[dmim]PF6 and PEO/[bmim]PF6 also indicated that the material containing the smaller cation [dmim]+ exhibits more significant slowing down on the dynamics of PEO chains. Clear indications of reduced strength in ion correlations are the distinct time evolution of van Hove correlation functions for anions and cations, and the higher κ/κNE ratio in comparison with, for instance, the PEO/LiClO4.
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Nixon, Emily Cummings. "Silanes in sustainable synthesis: applications in polymer grafting, carbon dioxide capture, and gold nanoparticle synthesis." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45847.
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Vinyltrialkoxysilanes are grafted onto polyolefins via a radical mechanism; in a subsequent step, the pendant alkoxysilanes hydrolyze and condense upon exposure to water, resulting formation of crosslinks. Straight chain hydrocarbons were used as model compounds to investigate the regioselectivity of vinyltrimethoxysilane grafting. To stabilize the water-sensitive grafted products, the methoxy groups were substituted using phenyllithium. It was found that this reaction must be carried out for a minimum of three days to ensure full substitution. The grafted products were then separated on a weight basis using semi-preparative HPLC. Analysis of the di-grafted fraction using edited HSQC and HSQC-TOCSY NMR showed that radical propagation occurs via 1,4- and 1,5-intramolecular hydrogen shifts along the hydrocarbon backbone, resulting in multiple grafts per backbone. Post-combustion carbon capture targets CO₂ emissions from large point sources for capture and sequestration. A new class of potential carbon capture agents known as reversible ionic liquids (RevILs) has been synthesized and evaluated in terms of potential performance parameters (e.g. CO₂ capacity, viscosity, enthalpy of regeneration). These RevILs are silylated amines, which react with CO₂ to form a salt comprising an ammonium cation and a carbamate anion that is liquid at room temperature. Structural modifications of the basic silylamine skeleton result in drastic differences in the performance of the resulting RevIL. Systematic variation of the silylated amines allowed determination of a structure-property relationship, and continued iterations will allow development of an ideal candidate for scale-up. The properties and potential applications of gold nanoparticles (AuNP) are highly dependent on their size and shape. These properties are commonly controlled during liquid-phase synthesis through the use of capping agents, which must be removed following synthesis. Reverse micelles can also be used to control the morphology of AuNP during their synthesis. When RevILs are used in the formation of these reverse micelles, either as the disperse phase or as the surfactant, the built-in switch can be used to release the nanoparticles following their synthesis. This release on command could decrease the post-synthetic steps required to clean and purify AuNP prior to use. We have successfully synthesized AuNP using a number of different RevILs.
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Chen, Ying. "NMR Applications in Soft Materials Science: Correlation of Structure, Dynamics, and Transport." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/75177.
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This dissertation aims to investigate and correlate structure, dynamics and transport properties of several novel soft materials systems using multiple Nuclear Magnetic Resonance (NMR) methodologies, including solid-state NMR (SSNMR), diffusometry, and imaging, and with the help of X-ray scattering.
First, we report the investigation of structure and dynamics of three polymeric membranes: hydroxyalkyl-containing imidazolium homopolymers, poly(arylene ether sulfone) segmented copolymers, and disulfonated poly(arylene ether sulfone) random copolymers using a wide array of SSNMR techniques, including: 1) ¹³C cross-polarization magic angle spinning (CPMAS) with varying cross-polarization (CP) contact time, 2) ¹³C single-pulse magic angle spinning (MAS) with varying delay time, 3) ²³Na single-pulse MAS, 4) two dimensional phaseadjusted spinning sideband (2D PASS), 5) proton spin−lattice relaxation (T₁), 6) rotating frame spin−lattice relaxation (T₁ρ), and 7) center-band-only detection of exchange (CODEX). These various types of SSNMR spectroscopic methods provide a wealth of structural and dynamic information over a wide range of time scales from a few nanoseconds to seconds.
We further present a picture of rich structural and transport behaviors in supramolecular assemblies formed by amphiphilic wedge molecules using a combination of ²³Na solid-state NMR, ¹H/²H PFG NMR diffusion, relaxation and grazing-incidence small-angle X-ray scattering. Our results show that the liquid crystalline domains in these materials undergo a transition from columnar to bicontinuous cubic phases with a simple increase in humidity, while the amorphous domain boundaries consist of individual wedge molecules with a significant fraction (~ 10%) of total wedge molecules. Multiple-component diffusion of both wedges and water further confirms the structural and dynamic heterogeneity, with the bicontinous cubic phase being able to facilitate much faster water and ion transport than the columnar phase.
We then develop a quantitative approach to probe the migration of two novel “theranostic” polymeric agents (combining “therapeutic” and “diagnostic” functions) into bulk hydrogels using two distinct time-resolved magnetic resonance imaging (MRI) methods. To the best of our knowledge, this is the first work that combines time-resolved MRI experiments to reliably quantify diffusivity of paramagnetic and superparamagnetic nanoparticles in bulk biological media. Our results agree closely with those obtained from fluorescence techniques, yet the capability of our approach allows the analysis of actual nanoparticles diffusion through biogels on mm to cm scales during a range of time periods.
Finally, we employ a combination of NMR techniques to obtain a comprehensive understanding of ion clustering and transport behaviors of ionic liquids inside the benchmark ionic polymer Nafion. Spin relaxation shows that anion relaxation is more influenced by the fixed sulfonate groups than cation relaxation. 2D ¹H-¹⁹F heteronuclear Overhauser effect spectroscopy (HOESY) and 1D ¹⁹F¹⁹F selective nuclear Overhauser effect (NOE) spectroscopy confirm our assumption of the formation of ion clusters at low water content in the ionomer. While we observe non-restricted diffusion behavior for cations, anion diffusion is strongly restricted both between domain boundaries and within domains in the absence of water. The restricted anion diffusion can serve as a reliable probe for detailed multiscale structures of the ionomer.Ph. D.
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Zhang, Chengda. "SYNTHESES OF PEG/ALKYL-BASED IMIDAZOLIUM/PYRIDINIUM IONIC LIQUIDS AND APPLICATIONS ON H2S ABSORPTION& SYNTHESES OF POLYSULFONE BASED FUNCTIONALIZED IMIDAZOLIUM IONIC POLYMERS AND APPLICATIONS ON GAS SEPARATION." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/theses/1797.
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The synthesis method for PEG/alkyl-based imidazolium/pyridinium ionic liquids was studied. Four steps were used to fabricate the membranes: polymerization, chloromethylation, linkage of the polymers with the pendent groups and membrane cast. Permeabilities and CO2/N2 selectivity of two membranes were examined and each showed remarkable CO2/N2 selectivity. CO2 permeability of the [PSM-MIM][Cl] membrane is better than that of the [PSM-MEIM][Cl] membrane, which is due to the steric hindrance of the methoxyethyl group. The syntheses of PEG/alkyl-based imidazolium/pyridinium ionic liquids (IL) were studied. PEG-based ILs were demonstrated to have better H2S solubilities than the alkyl-based ILs. H2S solubilities of the imidazolium ILs and pyridinium ILs were compared. The anion effects on H2S solubilities have been investigated, while the temperature effects on H2S solubilities will need to be studied in the near future.
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Pena, Ricardo. "Polymeric liquid crystals as potential processing aids." Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/9138.
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Rynkowska, Edyta. "Matériaux innovants à base de polymères et de liquides ioniques." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR012/document.
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Au cours des dernières décennies, les technologies membranaires ont largement contribué à l’amélioration des procédés de séparation à l’échelle industrielle grâce à de nombreux avantages, tels que la sélectivité de la séparation élevée, la possibilité de travailler avec des composés thermolabiles et la faible demande en énergie, ainsi que la possibilité de combiner les technologies membranaires avec d'autres procédés de séparation. Le procédé de pervaporation est une technique de séparation membranaire importante utilisée pour séparer les mélanges liquides binaires ou multicomposants, y compris les solvants à point d’ébullition proche, les mélanges azéotropes et les isomères. Il s’agit du transfert sélectif de matière à travers une membrane dense. Au cours de cette opération, le perméat sous forme vapeur est condensé sur une paroi froide, mais, contrairement à la distillation, seule une faible partie de la charge subit ce changement d’état. Les membranes utilisées dans la pervaporation doivent posséder une forte sélectivité, une stabilité chimique et une résistance mécanique à haute température élevées. La sélectivité et les propriétés de transport de la membrane déterminent l'efficacité globale du processus de séparation. La caractérisation approfondie des membranes est cruciale pour bien comprendre l’influence de la structure de la membrane et des conditions de préparation de la membrane sur les caractéristiques d’équilibre, de séparation et de transport des membranes étudiées, en vue de développer de nouveaux matériaux polymères efficaces. Les nombreuses recherches ont également été menées sur le développement des membranes avec de liquides ioniques (LIs) afin de personnaliser les propriétés de séparation des membranes utilisées dans la séparation des liquides par pervaporation, la séparation des gaz et la séparation des ions métalliques ainsi que les membranes conductrices dans les piles à combustible. Les LIs sont caractérisés par une bonne stabilité thermique, une conductivité ionique élevée, une pression de vapeur négligeable et un point de fusion assez bas. En raison de leurs nombreuses propriétés uniques, les membranes polymères contenant des LIs possèdent une large gamme d'avantages, comme de meilleures propriétés de séparation que les membranes polymères classiques. Ce fait est lié à une diffusion moléculaire beaucoup plus élevée dans un liquide ionique que dans des polymères. Par conséquent, l'utilisation de membranes à base de polymères et LIs dans les processus de séparation permettrait une sélectivité de séparation élevée et des flux plus importants. La structure et les propriétés physicochimiques des LIs peuvent être ciblées en fonction de l’application afin d'obtenir un matériau polymère approprié. En revanche, même si l’application de membranes hybrides à base de polymères et LIs suscite un intérêt croissant, leur utilisation dans les procédés de séparation reste limitée en raison des pertes de LI non lié. Cette thèse de doctorat en co-tutelle est réalisée entre la Faculté de Chimie de l'Université Nicolaus Copernicus (NCU) à Toruń (Pologne) et le Laboratoire Polymères, Biopolymères, Surfaces UMR 6270 CNRS de l’Université de Rouen Normandie (France). L’objectif principal de la thèse est d’élaborer de nouvelles membranes denses à base de poly (alcool vinylique) (PVA) et d’acétate-propionate de cellulose (CAP) et de divers LIs réactifs et polymérisables ceci afin d’obtenir un système polymère-liquide ionique dans lequel le LI est stabilisé par liaison covalente avec les chaînes macromoléculaires du polymère. L'étude des propriétés physicochimiques et d'équilibre des membranes a été effectuée ainsi que l’analyse de leurs propriétés de transport. De plus, les membranes sélectionnées ont été testées dans un processus de pervaporation en contact avec le mélange eau-propane-2-olIn the last decades, membrane separation has played an important role in many industrial processes thanks to its versatility, low energy consumption, high performances of membranes, as well as a possibility of combining membrane technologies with other separation processes. Membrane technologies gave a great contribution to the improvement of separation processes in the industrial scale thanks to a number of advantages, such as the high selectivity of the separation, the opportunity to work with thermolabile compounds, and low energy demand. Pervaporation process is an important membrane separation technique used to separate binary or multicomponent liquid mixtures including close boiling solvents, azeotrope mixtures, and isomers. During pervaporation, feed components are in the direct contact with one side of the lyophilic membrane, while the selected components are preferentially transported across the membrane to the permeate side. Membranes used in pervaporation must be characterized by high selectivity, chemical stability, and mechanical strength at high temperatures. Selectivity and transport properties of the membrane determine the overall efficiency of the separation process. The comprehensive characterization of membranes is the crucial approach and can lead to broaden the knowledge about the influence of the membrane structure and membrane preparation conditions on the equilibrium, separation, and transport characteristics of the studied membranes, in order to develop new polymer materials with the expected efficiency of the separation process. Research has been also focused on the development of the membranes filled with ILs in order to tailor the separation properties of the developed membranes used in liquid separation by pervaporation, gas separation, and separation of metal ions as well as the conducting barriers in fuel cells. ILs are characterized by good thermal stability, high ionic conductivity, negligible vapor pressure, and low melting point. Due to their numerous unique properties, polymer membranes containing ILs (polymer-ILs) possess wide range of advantages, like better separation properties than the classical polymer membranes. This fact is related with much higher molecular diffusion in ionic liquid than in polymers. Therefore, the use of polymer-ILs in separation processes would result in superior separation behavior and higher fluxes. Morphology and physicochemical properties of ILs can be “tailored” depending on the separated system in order to obtain a suitable polymer material for a given separation process without preparation of a chemically new membrane. Even though there is a growing interest in the application of polymer membranes filled with ILs, the polymer-ILs based separation processes are limited due to the losses of the unbound ionic liquid in the course of the exploitation. The PhD is realized in the frame of "co-tutelle" system between the Faculty of Chemistry at the Nicolaus Copernicus University (NCU) in Toruń, Poland (Membranes and Membrane Separation Processes Research Group) and the University of Rouen Normandy, France (Barrier Polymer Materials and Membranes (MPBM) Research Group of the Laboratory of Polymers, Biopolymers, Surfaces (PBS)). The main aim of the present PhD thesis is to elaborate novel dense membranes based on poly(vinyl alcohol) (PVA) and cellulose acetate propionate (CAP) filled with various reactive and polymerizable ILs in order to obtain the polymer-ionic liquid system in which ionic liquids are linked inside the polymer structure. The investigation of physicochemical characteristics and study of the equilibrium, barrier, and transport properties of the obtained membranes was carried out. Furthermore, the selected membranes were tested in pervaporation process in contact with water-propan-2-ol mixture, water and gas permeation measurements
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Jenkins, Shawn Eric. "Synthesis and spinning of a new thermotropic liquid crystallinepolymers : characterization of fiber morphology and mechanical properties." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/8557.
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Luo, Shijian. "Synthesis and charaterization of chiral 2-methyl-1,4-cyclohexanedicarboxylic acid and its polyamide." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/8606.
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Wusik, Martin Joseph. "The synthesis and characterization of a regularly alternating copolyester." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/8708.
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Zhou, Jian. "Study of Anchoring Behavior of Nematic Fluids at The Interface of Polymer-Dispersed Liquid Crystals." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/5121.
Full textAbstract:
A liquid crystal (LC) at its boundary surface adopts a preferential alignment, which is referred to as anchoring. The direction of this alignment (i.e., anchoring direction) may be perpendicular, parallel or tilted with respect to the surface. Transitions from one anchoring condition to another may occur when the parameters (e.g., temperature) charactering the surface change, as referred to as anchoring transitions. In the LC-polymer composite systems under our study, the anchoring and temperature- driven anchoring transitions of nematic fluids is very sensitive to the structure of the side chain of poly (alkyl acrylate) matrixes that encapsulate the LC. We have shown that the anchoring transition temperature of these systems can be tuned far below the nematic-to-isotropic transition temperature, by varying either the length, branching structure of the side chains of homopolymers, or the composition of copolymer of two dissimilar monomers. Both sharp and broad anchoring transitions with respect to the temperature range over which a transition occurs were observed. It is postulated that microscopic interactions between the polymer side chains and LC molecules play an important role in determining the anchoring. In particular, the conformation of the polymer side chain is proposed to have important control over the anchoring. Anchoring strength and tilt angle as a function of temperature during the anchoring transitions were also experimentally investigated, which contribute to understanding of the microscopic mechanism for such transitions.
Based on the LC-polymer composites with controlled anchoring, a LC display with reverse switching mode and a novel electrically switchable diffraction grating have been demonstrated. The advantages of these devices are ease of manufacturing, low operation voltage, and mechanical stability offered by polymer matrix.
Moreover, a detailed study of the director configuration of wall defects found in these composite films was carried out using fluorescence confocal polarized microscopy.
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Yang, Junhong. "GLASS FORMATION BEHAVIOR AND IONIC CONDUCTIVITY OF IONIC LIQUIDS AND POLYMERIC IONIC LIQUID: INSIGHT FROM MOLECULAR SIMULATION." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1494886213137829.
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Bara, Jason Edward. "New ionic liquids and ionic liquid-based polymers and liquid crystals for gas separations." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3256439.
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Wiggers, Joram. "Analysis of textile deformation during preforming for liquid composite moulding." Thesis, University of Nottingham, 2007. http://eprints.nottingham.ac.uk/10414/.
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Fibre Reinforced Plastics offer several advantages over other materials such as decreased part counts, weight savings, and flexibility. The obstacles to the further expansion of composites use, particularly in cost-conscious industries such as the car industry, include volume, cost, and quality. Liquid Composite Moulding, where the dry textile reinforcement is shaped prior to application of the plastic matrix, offers to address these drivers by offering potential for automation, speed, and quality control. However, the preforming of the dry reinforcement is rarely automated, and its results are variable and hard to predict or control. This thesis aims to facilitate better preforming process design and control. The dominant deformation mechanism that allows reinforcements to conform to a 3D surface is trellis shear. Work is therefore presented on shear characterisation of textile reinforcements using the picture frame and the bias extension tests. Several approaches to normalising these tests to achieve method-independent shear data are proposed, and compared. Of these, a normalisation technique for the bias extension test based on energy considerations appears to be the most appropriate. A constitutive modelling approach, based on the meso-mechanical deformation mechanisms identified in the reinforcement, is developed for characterising the asymmetric shear properties exhibited by non-crimp fabrics. The results from this model are compared with experimental data. Finally, an energy minimising kinematic drape method is developed to account for the use of automated reinforcement blank-holders, and methods for modelling process variability using the code are investigated.
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Moilanen, A. (Anu). "Self-association, compatibility, and strengthening behavior of liquid crystalline oligomers." Doctoral thesis, University of Oulu, 1998. http://urn.fi/urn:isbn:9514250915.
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Abstract
Synthetic routes were developed for the preparation of 2-alkoxy-4-hydroxybenzoic
acids and 2-alkoxyhydroquinones, and a large-scale synthesis was
developed for the preparation of 2-thioalkoxyhydroquinones. The
2-alkoxy-4-hydroxybenzoic acids, which contained alkyl side chains of
different length, were used in the synthesis of new main chain liquid
crystalline (LC) homo-, random, and block co-oligomers. In addition,
oligomers of terephthaloyl chloride and 2-thioalkoxyhydroquinones
and oligomers of terephthaloyl chloride and 2-alkoxyhydroquinones
were produced.
All the oligomers were blended with aliphatic polyamide 11
(PA 11). The effect of alkyl side chain length on the compatibility
behavior of the LC oligomers towards the aliphatic polymer was characterized
by DSC and FTIR, and the effect of side chain length on the flexural
properties of the blends was investigated with a three-point bending
test.
The miscibility studies showed variable interfacial adhesion
between the blended compounds. The strongest adhesion was achieved
between PA 11 and the homo-oligomers of 2-alkoxy-4-hydroxybenzoic
acids with short or medium long substituents (C4-C10),
but the interactions between PA 11 and the oligomer with long aliphatic
side chain (C18) were poor, as were those
between PA 11 and the wholly aromatic oligomer of 4-hydroxybenzoic
acid. The compatibility between PA 11 and the co-oligomers of 2-alkoxy-4-hydroxybenzoic
acids was slightly lower than the compatibility of the corresponding
homo-oligomers. DSC and FTIR analyses of the blends of oligomers
of terephthaloyl chloride and 2-thioalkoxyhydroquinones and oligomers
of terephthaloyl chloride and 2-alkoxyhydroquinones with PA 11 implied
that the interactions between the blended compounds were poor.
FTIR spectra and viscosity measurements confirmed that all
the oligomeric structures could self-associate, with effect on the
final mechanical properties of the polyamide. The strength of PA
11 in a three-point bending test was increased by the addition of
only 1% of LC oligomers to the matrix. The results also
showed that the strengthening ability of the oligomers is directly
proportional to the total amount of aliphatic carbons. The best
strengthening results were obtained with unsubstituted oligomers,
random co-oligomers of 2-alkoxy-4-hydroxybenzoic acids, and homo-oligomer
of 2-butoxy-4-hydroxybenzoic acid.
DSC investigations of a ternary blend of the oligomer of 2-decanyloxy-4-hydroxybenzoic
acid, PA 11, and wholly aromatic commercial LC polymer showed the
promising compatibilizing effect of the oligomer.
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Bai, Yiqun. "Structure and properties of linear and star-like thermotropic liquid crystalline polymeric fibers." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/9976.
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Javaid, Salman. "Some aspects of ionic liquid blends and additives influencing bulk conductivity of commercial base paper." Thesis, Karlstads universitet, Avdelningen för kemiteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-26775.
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In this study, bulk conductivity of commercial base paper impregnated with different ionic liquids blends and additives, through bench coating was investigated. Bulk conductivity of base paper, ion conductive paper and surface sized ion conductive papers with and without the influence of calendering were evaluated at different concentrations of ionic liquids using at resistivity cell and four point probe technique. It was shown that bulk conductivity of base paper was increased by increasing the amount of ionic liquids. Nano fibril cellulose also showed positive influence on the bulk conductivity of coated papers. By increasing the line load in the calendering machine, a positive influence on the bulk conductivity was observed. The tensile index of all the coated papers was lower than that of the base paper.
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Conlin, Emma L. "Design and synthesis of liquid crystalline polymer brushes and hydrogen bonded polymers /." Available to subscribers only, 2005. http://proquest.umi.com/pqdweb?did=1079664771&sid=2&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Lee, Myongsoo. "Molecular engineering of liquid crystal polymers by living polymerization." Case Western Reserve University School of Graduate Studies / OhioLINK, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=case1060091978.
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Blasucci, Vittoria Madonna. "Organic solvents for catalysis and organic reactions." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31723.
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Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2010.Committee Chair: Charles Eckert; Committee Co-Chair: Charles Liotta; Committee Member: Amyn Teja; Committee Member: Christopher Jones; Committee Member: William Koros. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Ahn, Sangbum. "Synthesis and Functionalities of Conjugated Polymers with Controllable Chirality and Low Bandgaps." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199335.
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Pugh, Coleen Renee. "Model compounds for liquid crystal polymers containing rod-like and disk-like mesogens." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1059486231.
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Sood, Rakhi. "Electrolytes polymère nano-structurés à base de liquides ioniques pour les piles à combustible hautes températures." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00819818.
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Les membranes à base de liquides ioniques à conduction protonique (PCIL) sont très prometteuses comme électrolytes des piles à combustible haute température (HT- PEMFC) du fait de leur forte conductivité et stabilité à des températures supérieures à 100°C. L'objectif de cette thèse est de réaliser une étude approfondie sur l'évolution de la morphologie et des propriétés fonctionnelles, des membranes à base de liquides ioniques, avec i) la concentration en PCIL, ii) la méthode d'élaboration et iii) la structure chimique du PCIL. Afin de prouver la potentialité de ces membranes dans le HT-PEMFC, des tests préliminaires en pile sont réalisés et les phénomènes de dégradation des PCIL et des membranes en présence de peroxyde d'hydrogène sont étudiés. La première partie de ce travail est focalisée sur la caractérisation des membranes de Nafion® neutralisées avec le triéthylamine (Nafion-TEA) et gonflées avec triflate de triéthylammonium (TFTEA). Il a été montré que dans le Nafion-TEA sec, les cations présentent une organisation de type " string like " à l'interface hydrophobe-hydrophile. L'introduction du TFTEA dans la membrane Nafion-TEA ne détruit pas sa nano-structuration, mais augmente de manière significative la conductivité ionique du système. La deuxième partie de ce travail nous a permis d'établir que les membranes dopées élaborées par coulée-évaporation présentent une meilleure organisation et une meilleure tenue thermomécanique par rapport à celles obtenues par gonflement. La troisième partie de ce travail est focalisée sur l'étude de l'impact de la nature chimique du PCIL sur la morphologie et les propriétés fonctionnelles des membranes de Nafion-TEA. Il a été démontré que les PCILs avec longues chaînes perfluorées ne modifient pas la nano-structuration du Nafion-TEA. Ceci a un impact fort sur les propriétés de conductivité, de sorption d'eau et sur les propriétés thermomécaniques de la membrane. Dans la dernière partie, des Ionomères aromatiques ont été synthétisés afin de remplacer le Nafion-TEA. Malgré la structure similaire de la chaîne latérale des Ionomères aromatiques et du Nafion®, les membranes à base d'Ionomères aromatiques et TFTEA ne présentent aucune nano-structuration. De plus l'effet plastifiant du TFTEA est plus notable dans le cas des Ionomères aromatiques probablement du fait d'une distribution aléatoire des fonctions ioniques dans la membrane polymère.
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Sorrie, Graham A. "Liquid polymer electrolytes." Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU499826.
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This thesis is concerned with ion-ion and ion-polymer interactions over a wide concentration range in polymer electrolytes with a view to shedding new light on the mechanism of ion migration. Additionally, the electrochemical stability window of these electrolytes on platinum and vitreous carbon electrodes has been thoroughly investigated. The final part of this thesis is concerned with determining the feasibility of polymer electrolytes as electrolytes in a new type of energy storage device, a double layer capacitor which incorporates activated carbon cloth electrodes. Conductivities and viscosities of solutions of Li, Na and K thiocyanates in low-molecular-weight, non-crystallizable liquid copolymers of ethylene oxide (EO) and propylene oxide (PO) have been measured. The curves of molar conductance versus sqrt c show well-defined maxima and minima. The conductivity is independent of copolymer molecular-weight but is enhanced by raising the EO content of the copolymer. The results are interpreted in terms of a model for ion migration in which ion association and redissociation effects play an important role. It is proposed that the characteristic properties of liquid polymer electrolytes can only be satisfactorily explained if the current is largely anionic. The electrochemical stability window of these electrolytes on platinum is dominated by the presence of a water reduction peak starting at approximately -1.0V which limits the overall stability to approximately 2V. The onset of water reduction is displaced to more negative potentials (-3.0V), thus increasing the stability window, on vitreous carbon electrodes. The value of the double layer capacitance on vitreous carbon electrodes (15-30muF cm-2) agrees well with published data. The double layer capacitance of activated carbon cloth electrodes is lower than anticipated. The importance of faradaic charging and discharging currents to the successful operation of double layer capacitors is indicated but no problems relating to the specific use of polymer electrolytes in such devices were found.
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Montibon, Elson. "Modification of Paper into Conductive Substrate for Electronic Functions : Deposition, Characterization and Demonstration." Doctoral thesis, Karlstads universitet, Avdelningen för kemiteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-7352.
Full textAbstract:
The thesis investigates the modification of paper into an ion- and electron-conductive material, and as a renewable material for electronic device. The study stretches from investigating the interaction between the cellulosic materials and the conducting polymer to demonstrating the performance of the conductive paper by printing the electronic structure on the surface of the conductive paper. Conducting materials such as conducting polymer, ionic liquids, and multi-wall carbon nanotubes were deposited into the fiber networks. In order to investigate the interaction between the conducting polymer and cellulosic material, the adsorption of the conducting polymer poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonate) (PEDOT:PSS) onto microcrystalline cellulose (MCC) was performed. Electroconductive papers were produced via dip coating and rod coating, and characterized. The Scanning Electron Microscopy (SEM) / Energy Dispersive Spectroscopy (EDS) images showed that the conducting polymer was deposited in the fiber and in fiber-fiber contact areas. The X-ray Photoelectron Spectroscopy (XPS) analysis of dip-coated paper samples showed PEDOT enrichment on the surface. The effects of fiber beating and paper formation, addition of organic solvents and pigments (TiO2, MWCNT), and calendering were investigated. Ionic paper was produced by depositing an ionic liquid into the commercial base paper. The dependence to temperature and relative humidity of the ionic conductivity was also investigated. In order to reduce the roughness and improve its printability, the ionic paper was surface-sized using different coating rods. The bulk resistance increased with increasing surface sizing. The electrochemical performance of the ionic paper was confirmed by printing PEDOT:PSS on the surface. There was change in color of the polymer when a voltage was applied. It was demonstrated that the ionic paper is a good ionic conductor that can be used as component for a more compact electronic device construction. Conductive paper has a great potential to be a flexible substrate on which an electronic structure can be constructed. The conduction process in the modified paper is due to the density of charge carriers (ions and electrons), and their short range mobility in the material. The charge carrying is believed to be heterogeneous, involving many charged species as the paper material is chemically heterogeneous.Fel ordningsnummer (2010:28) är angivet på omslaget av fulltextfilen.
Printed Polymer Electronics on Paper
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Leyral, Géraldine. "Synthèse et structuration de sulfure de molybdène promu nickel en présence de liquide ionique ou de polymère hydrosoluble amphiphile : application en catalyse hétérogène." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20266.
Full textAbstract:
Avec l’épuisement progressif des ressources pétrolières, la production de biocarburant est actuellement en plein développement. Utiliser la biomasse en tant que source d’énergie permettrait également de limiter la concentration en dioxyde de carbone dans l’atmosphère et ainsi l’effet de serre. Cependant son processus de transformation implique une étape d’hydrodésoxygénation qui nécessite d’avoir recours à des catalyseurs de type sulfure de molybdène dopé par du cobalt ou du nickel. Ces catalyseurs sont également indispensables au cours du traitement du pétrole lors du procédé d’hydrodésulfuration qui est primordial pour limiter la pollution de l’air par les gaz de combustion des carburants. Cette thèse propose une méthode de synthèse et de structuration de catalyseurs massiques NiMoS facile à mettre en œuvre et rapide. Deux solvants ont été utilisés : l’eau et le formamide. L’ajout d’un polymère hydrosoluble amphiphile, le PEO113-b-PLLA32, dans l’eau et de liquides ioniques (BMIMNTf2 et BMIMBF4) dans le formamide ont permis la structuration des matériaux et l’obtention de surfaces spécifiques atteignant 55 m2g-1. Ceci représente une surface importante pour ce type de composé, en particulier dans le cadre d’une synthèse par chimie douce. Les premiers tests catalytiques réalisés vis-à-vis de la réaction d’hydrodésoxygénation de l’acide décanoïque montrent une activité catalytique très prometteuse pour ces matériauxWith the progressive decrease of oil resources, the production of biomass fuel is a fast growing field. This could limit the concentration of carbon dioxide in the atmosphere and thus the global warming. The production of this kind of fuel requires the use of catalysts such as nickel or cobalt promoted molybdenum sulfide. These materials are also crucial during the refining of oil, an essential step to limit atmospheric pollution during the classic fuel combustion. New methods to synthesize and structure NiMoS catalysts have been developed in this work. Two solvants have been studied: formamide and water. The addition of an amphiphilic water-soluble polymer (PEO113-b-PLLA32) in water and of ionic liquids (BMIMNTf2 and BMIMBF4) in formamide led to the structuring of the materials with specific surface areas up to 55 m2g-1. This is a high value for this kind of material, especially since the synthesis is carried out under soft conditions. The first catalytic tests dealt with decanoïc acid hydrodesoxygenation and highlighted a promising activity for these materials